Unit 5
Text Study: Output Devices. Printers.
Additional Text: Disks and Tapes.
Grammar: Revision of the Module.
Text Study
1. Repeat the words in
chorus:
Permanent,
human-readable, to identify, a ribbon, requirements, quality, an observer, variety,
to create.
2.
While reading the text you will come across a number of international words.
Try to guess what Ukrainian words they remind of you:
A
printer, a component, a design, electromechanical, a mechanism, typically, magnetic,
a line, cylindrical, a minute, electrophotographic.
3. Pay attention to some
grammatical points:
1) Printers that use electromechanical mechanisms that cause hammers to strike against a
ribbon and the paper are called impact
printers. 2) Character printers are
the type used with literally all
microcomputers as well as on
computers of all sizes whenever the printing requirements are not large. 3) Character
printers may be of several types. 4)
It sprays small drops of ink onto
paper to form printed characters. 5) Line printers have been designed to use many different types of printing
mechanisms. 6) A variety of techniques are
used in the design of page printers. 7) These techniques, called electrophotographic techniques, have developed from the paper copier technology.
II.
Reading
Read the text and be ready to
find in the text the answers to the following questions:
·
What types of printers
are there??
Output Devices. Printer
Printers provide
information in a permanent, human-readable form. They are the most commonly
used output devices and are components of almost all computer systems. Printers
vary greatly in performance and design. We will classify printers as character
printers, line printers and page printers in order to identify three different
approaches to printing, each with a different speed range. In addition,
printers can be described as either impact or nonimpact. Printers that use
electromechanical mechanisms that cause hammers to strike against a ribbon and
the paper are called impact printers. Nonimpact printers do not hit or impact a
ribbon to print.
Character printers
print only one character at a time. A typewriter is an example of a character
printer. Character printers are the type used with literally all microcomputers
as well as on computers of all sizes whenever the printing requirements are not
large. Character printers may be of several types. A letter-quality printer is
a character printer which produces output of typewriter quality. Letter-quality
printers typically have speeds ranging from 10 to 50 characters per second.
Dot-matrix printers form each character as a pattern of dots. These printers
have a lower quality of type but are generally faster printers than the
letter-quality printers — in the range of 50 to 200 characters per second. One
of the newest types of character printer is the ink-jet printer. It sprays
small drops of ink onto paper to form printed characters. The ink has high iron
content, which is affected by magnetic fields of the printer. These magnetic
fields cause the ink to take the shape of a character as the ink approaches the
paper.
Line printers are
electromechanical machines used for high-volume paper output on most computer
systems. Their printing speeds are such that to an observer they appear to be
printing a line at a time. They are impact printers. The speeds of line
printers vary from 100 to 2500 lines per minute. Line printers have been
designed to use many different types of printing mechanisms. Two of the most
common print mechanisms are the drum and the chain. Drum printers use a solid,
cylindrical drum, rotating at a rapid speed. Speeds of drum printers vary from
200 to over 2000 lines per minute. Chain printers have their character set on a
rapidly rotating chain called a print chain. Speeds of chain printers range
from 400 to 2400 lines per minute.
Page printers are
high-speed nonimpact printers. Their printing rates are so high that output
appears to emerge from the printer a page at a time. A variety of techniques
are used in the design of page printers. These techniques, called
electrophotographic techniques, have developed from the paper copier
technology. Laser-beam printers use a combination of laser beam and
electrophotographic techniques to create printer output at a rate equal to
18000 lines per minute.
Vocabulary Notes
human-readable form – зручна для читання форма
performance [pq'fLmqns] –
(робоча) характеристика; продуктивність; швидкість роботи; пропускна здатність
a character printer – пристрій друку символами
a line printer – пристрій друку рядками
a page printer – пристрій друку сторінками
(non) impact printer – (без)контактний принтер
letter-quality ['kwOlItI] printer – принтер с топографічною
якістю друку
dot-matrix printer – крапково-матричний принтер
an ink-jet printer – струйний принтер
a laser-beam printer – лазерний принтер
an approach [q'prqutS] – підхід; метод; принцип; наближення
at a time –
за один раз; одночасно
to cause – викликати; змушувати;
примушувати
a typewriter – пристрій для друкування
to spray drops of ink – розпилювати краплі
чорнила
to affect – впливати; впливати;
виявлятись
a technique [tek'nJk] – метод; спосіб; техніка; методика; технологія
printer output – вивід для друку; дані, що роздруковуються
Comprehension
1.
Tell what sentences are true and what are false.
1) Printers provide
information in a permanent, human-readable form. 2) Printers are commonly used input
devices. 3) We classify printers as character printers and line printers. 4) A
typewriter is an example of a line printer. 5) One of the newest types of
character printer is the ink-jet printer that sprays small drops of ink onto
paper to form printed characters. 6) Line printers are electromechanical
machines used for high-volume paper output on most computer systems. 7) Page
printers are low-speed nonimpact printers because their printing rates are low.
2.
Choose the right answer:
1) Printers are the most commonly
used … devices
a) input;
b) output;
c) storage.
2) Printers that use electromechanical mechanisms
that cause hammers to strike against a ribbon and the paper are called … .
a) impact printers;
b) nonimpact printers;
c) low-speed printers.
3) Character printers print only …
at a time.
a) three characters;
b) two characters;
c) one character.
4) Line printers are
electromechanical machines used for … output on most computer systems.
a) high-volume paper;
b) low-volume paper;
c) mid-volume paper.
5) Page printers are high-speed …
printers.
a) nonimpact;
b) impact;
c) line.
3. Complete the
sentences:
1) There are
several kinds of printers … . 2) Printers vary greatly
in … . 3) The characteristic features of character
printers are … . 4) Character printers may be of
several types: … . 5) Line printers are … . 6) Two of the most common print mechanisms are … . 7) Drum printers use … . 8) Speeds
of drum printers vary from … to over … lines per minute.
9) Speeds of chain printers range from … to … lines
per minute. 10) Page printers are … .
4.
Answer the questions:
1) What are the
three types of printers? 2) What is a letter-quality printer? 3) What is a
dot-matrix printer? 4) What type of printer is the most common with
microcomputer systems? 5) What is the most common printer type used on large
computer systems? 6) What is an impact printer? Give an example. 7) What is a
nonimpact printer? Give examples. 8) What are the most widely used printers? 9)
How do you distinguish between a letter-quality printer and a dot-matrix
printer? 10) Which of these printers is slower? 11) What types of character
printers do you know? 12) How are printed characters formed by means of an
ink-jet printer? 13) What are the main types of a line printer? Which of them
is faster? 14) What techniques are used in the operation of page printers?
5.
Find as quickly as possible and read out the sentences containing the following
important information:
*6.
Try to tell the gist of the text.
Word Study
1. Give Ukrainian equivalents of the
following.
To vary greatly in
performance and design, high iron content, commonly used output devices, human-readable
form, speed range, to print only one character, different approaches to
printing, impact or nonimpact printers, almost all computers, printing
requirements, as well as, ink-jet printer, typewriter quality, to spray small
drops of ink, to take the shape of a character, magnetic fields, appear to be
printing a line, a drum printer, a chain printer, lazer printer.
2. Give English
equivalents of the following.
Зручна для людського сприйняття
форма; найуживаніші засоби виводу інформації; відрізнятись робочими
характеристиками і зовнішнім виглядом; різні методи друку; діапазон швидкості;
контактні та безконтактні принтери; друкувати по одному символу; майже всі
комп’ютери; а також; вимоги друку; принтер с топографічною якістю друку;
струйні принтери; розпилювати краплі чорнила; високий вміст заліза; магнітні
поля; набирати форму символу; здається, що друкують по рядочку; барабанний
принтер; ланцюгові принтери; лазерний принтер.
3. Match the words in A with
their synonyms in B:
A B
human execution
performance person
an approach a method
to cause a way
to spray to make
to affect to
sprinkle
technique to influence
4. Fill in the gaps
with the words from Vocabulary Notes in the appropriate form.
a letter-quality / a typewriter / performance and
design / to identify / human-readable / line / nonimpact
1) Printers are
machines that provide information in a permanent, …
form. 2) Printers vary greatly in … . 3) We classify
printers as character printers, line printers and page printers in order …
three different approaches to printing. 4) … is an example of a character
printer. 5) … printer is a character printer which produces output of
typewriter quality. 6) … printers have been designed to use many different
types of printing mechanisms. 7) Page printers are high-speed … printers.
5. Translate sentences into English using
words and word combinations from the Vocabulary Notes.
1) Принтери видають інформацію у доступній для людей, читабельній
формі. 2) Принтери не всі однакові, так як відрізняються продуктивністю та
будовою. 3) Такі принтери, що друкують лише один символ за одиницю часу
називаються пристроями друку символами. Звичайно такими машинами великі об’єми
інформації надрукувати важко. 4) Лінійні принтери були названі таким чином, бо
їхня здається, що вони видруковують кожен рядок окремо. 5) Барабанний та
ланцюгові принтери – найпоширеніші друкарські механізми. 6) Пристрій друку
сторінками – це високошвидкісні, контактні принтери, які характеризуються
високою швидкістю друку.
The Grammar in Use
Revision
of the Module IV
1. Replace the
infinitive in brackets by the Present Perfect, the Past Perfect, the Future
Perfect or the Past Indefinite Tense.
1) Microsoft already (to create) its own standards in a market. 2) Microsoft (to revolutionize) the PC computing world and it (to put) much effort in to application integration and interoperability. 3) They (to say) that Microsoft (to design) its products with necessary components. 4) This system (to give) the user an enormous amount of power by 3 p.m. tomorrow. 5) When I (to come) she (to enter) the password and (to begin) working. 6) He (to receive) the e-mail by tomorrow. 7) They (to repair) the computer before they (to begin) typing. 8) You ever (to make) up a computer program? – Yes, I (to create) some last year. 9) At last I (to understand) the purpose of the operating system; now I’ll have a rest. 10) By this time you (to take) your examination on Information Technologies.
2. Put questions
to the underlined words.
1) We have discovered a security flaw in Microsoft’s Internet Explorer browser running under Windows 95. 2) Computers had enhanced the deadliness of weapons. 3) Computers will have attained human intelligence. 4) We have just received mail electronically on our computers. 5) I (to do) the computer exercises by 7 o’clock.
3. Transform the
following sentences into disjunctive questions.
1)
Usenet itself is a set of machines that exchanges messages or article, from
Usenet discussion forums, called newsgroups. 2) There are thousands of Usenet
newsgroups in existence. 3) Numerous newsgroups are organized around
recreational topics. 4) Chat programs allow users on the Internet to
communicate with each other by typing in real time. 5) They are sometimes
included as a feature of a Web site.6) These channels
are usually based on specific topics. 7)
A variation of chat is a phenomenon of instant messaging. 8) We made some new
programs yesterday.
Additional Text
(for
individual work)
Read
and translate the text.
Disks
and Tapes
There are two important groups of input/output (i/o)
devices. There are devices that provide data storage, like disks and tapes, and
there are devices that connect the computer system to the external world
(keyboards, printers, displays, sensors).
Most personal computers have two or three different types of disk
storage unit. There will be some form of permanently attached disk (the main
"hard disk"), some form of exchangeable disk storage (a "floppy
disk" or possibly some kind of cartridge-style hard disk), and there may
be a CD-ROM drive for read-only CD disks.
Optical disks. CD disks encode 0
and 1 data bits as spots with different reflectivity. The data can be read by a
laser beam that is either reflected or not reflected according to the setting
of each bit of data; the reflected light gets converted into a voltage pulse
and hence the recorded 0/1 data values gets back into the form needed in the
computer circuits. Currently, optical storage is essentially read-only – once
data have been recorded they can't be changed.
Magnetic disks. Most disks use
magnetic recording. The disks themselves may be made of thin plastic sheets
(floppy disks), or ceramics or steel (hard disks). Their surfaces are covered
in a thin layer of magnetic oxide. Spots of this magnetic oxide can be magnetically
polarized. If a suitably designed wire coil is moved across the surface, the
polarized spots induce different currents in the coil – allowing data to be
read back from the disk. New data can be written by moving a coil across the surface
with a sufficiently strong current flowing to induce a new magnetic spot with a
required polarity. There is no limit on the number of times that data can be rewritten
on magnetic disks. The bits are recorded in "tracks"
– these form concentric rings on the surface of the disk. Disks have hundreds
of these tracks. Tracks are too large a unit of storage – they can hold tens of
thousands of bits. Storage on a track is normally broken down into "blocks" or sectors. Nowadays,
the operating system
program that controls most of the operations of a computer will mandate a
particular block size. This is typically in the range 512 bytes to 4096 bytes
(sometimes more). The disk controller
may identify blocks by block number and track number.
Files. Data files on disk
are made up out of blocks. The operating system is responsible for choosing the
blocks used for each file, and for recording details for future reference. The
data in the blocks form a table of entries with each entry specifying a file
name, file size (in bytes actually used and complete blocks allocated), and
some record of which blocks are allocated. The allocation scheme uses a group
of contiguous blocks to make up each individual file. This makes it easy to
record details of allocated blocks, the directory need
only record the file size and the first block number.
File directory. In addition to the
table of entries describing allocated files, the directory structure would
contain a record of which blocks were allocated and which were free and
therefore available for use if another file had to be created. One simple
scheme uses a map with one bit for each block; the bit is set if the block is allocated.
Tapes. Tapes are now of
minor importance as storage devices for users' files. Mostly they are used for
"archival" storage – recording data that are no longer of active
interest but may be required again later. All the processes using tapes, like
skipping to file marks, sequential reads etc, are slow.
1. Divide the text into the
logical parts and give a title to each one.
2. Put questions to the text.
3.
Discuss it with your groupmates.